Waistline creep has become quite a bit more prevalent in the last decade--so much so, in fact, that one-third of the American population is obese and another third is overweight.
One unintended consequence of this is the risk of obese drivers dying in car crashes because they’re failing to buckle up.
Why wouldn’t they buckle up? In short, in many instances it’s because the seat belts don’t fit.
Reuters Health reported on a new study published online in the American Journal of Emergency Medicine, “Obesity and seatbelt use: a fatal relationship.” This was the largest investigation to date of a connection between seatbelt use and obesity.
The retrospective study analyzed a U.S. database of nearly 200,000 fatal car crashes and found that Americans of normal weight involved in those accidents were 66 percent more likely to have been buckled up than those who were severely obese.
The study’s lead author, Dr. Dietrich Jehle, commented to Reuters Health that “cars should be designed so it’s easier to put a seatbelt on if you’re obese.”
Back in the 1960s, when federal safety standards were set, Americans tended to be lighter. Those standards require seat belts to accommodate men weighing up to 215 pounds. That’s hardly the case today for many adults, male and female, who exceed that weight threshold.
Dr. Jehle, who is director of emergency services at Erie County Medical Center and vice chairman of Emergency Medicine at the State University of New York at Buffalo, said that some automakers offer larger seat belts or extenders, but that heavier people frequently have a difficult time with their car’s seat belts. They struggle to get strapped in, feel squeezed once they are and, as a result, unsnap the seat belt and drive unprotected.
Typically, obesity is defined by body mass index, or BMI. This is a measure of weight to height. A normal weight person has a BMI between 18.5 and 25. A BMI between 25 and 30 is considered to be overweight. Between 30 and 40 is obese, and above 40 BMI is classified as morbidly obese.
To put this into context, take the example of a 5-foot-10-inch tall man weighing 300 pounds. His BMI would be 43, morbidly obese.
A previous study found that drivers with a BMI of 40 had an 80 percent likelihood of dying in an accident.
Dr. Jehle’s team found that the closer to morbidly obese a person was, the less likely they were to have worn a seat belt.
Moderately-obese drivers, in comparison, were 23 percent more likely to have worn seat belts, while slightly obese drivers were 39 percent more likely. Overweight individuals were 60 percent more likely than morbidly obese drivers to have buckled up.
What’s the risk? Unbelted obese drivers are at greater risk of being subjected to higher impact forces and ejection from the vehicle. Both of these risks lead to more severe injuries and/or the possibility of death.
Jehle hopes the study will prompt automakers to make longer seat belts and to work with safety regulators to use larger crash-test dummies to be more reflective of the current population – one-third of which is overweight and one-third obese.
Nationally, according to statistics just released by the National Highway Traffic Safety Administration (NHTSA) (PDF), overall seat belt usage in 2013 reached 87 percent, statistically unchanged from 2012’s 86 percent. In states with laws where drivers can be pulled over and cited for not being belted in (“primary law states”), seat belt use was 91 percent, and in heavy-traffic areas, 90 percent.